Noble Tune finished second, 1 1/4 lengths back, and Balance the Books finished third. The winner -- trained in Ireland and raced in England, France and Ireland -- ran the 1 mile on the firm Santa Anita turf course in 1:33.78 with Ryan Moore aboard.
George Vancouver is a Kentucky-bred son of Henrythenavigator, who finished second in the 2008 Breeders' Cup Classic at Santa Anita. Aidan O'Brien trains the colt for Coolmore's Irish operation.
The Juvenile Turf was only the second win in seven races for George Vancouver. In his last previous effort, however, he was a good third behind Dawn Approach, a top 2013 Epsom Derby prospect, in the Group 1 Dubai Dewhurst Stakes at Newmarket. He earlier finished second in the Group 1 Darley Prix Morny at Deauville.
Noble Tune was 2-for-2 before Saturday's race, winning both his starts in New York.
Dundonnell, a Juddmonte Farms colt, finished fourth.